Embodiments of the inventive concept relate to buffer circuits (hereafter “buffers”), and more particularly buffers capable of correcting duty cycle distortions in an input signal. Embodiments of the inventive concept also relate to duty cycle correction methods using this type of buffers.
Buffers are routinely incorporated into the circuitry of various semiconductor devices (e.g., semiconductor memory devices, such as dynamic random access memory devices or DRAM) for many different purposes. Among other functionality, buffers may be designed to amplify relatively small (or weak) signals, such as many high speed signals applied to semiconductor memory devices, and output CMOS (Complementary Metal-Oxide-Semiconductor) compatible signal having greater immunity to system noise. However, such buffers do not conventionally correct the duty cycle of distorted input signals. When the duty cycle offset of an input signal is not corrected by a buffer, a set margin and a hold margin are inevitably decreased in a device receiving (and subsequently processing) the output signal provided by the buffer. In extreme cases, a semiconductor device may malfunction due to a duty cycle offset accumulated while an output signal of the buffer is being processed.